Luke Johnson, one half of the duo who turned Pizza Express into a national success story, has ruled out making a bid for the chain, saying it is challenged by low growth and discounting.

Mr Johnson, who with partner Hugh Osmond is responsible for the explosive growth of the pizza chain in the 1990s, said that he had no interest in making a return, and cautioned that it was discounting that killed some of the rival pizza chains he and Mr Osmond managed to put out of business.

Pizza Express has been placed on the market after private equity owner Cinven appointed Goldman Sachs to find a buyer for the business, which is worth in the region of £900m.

But Mr Johnson, whose Risk Capital Partners private equity house backs food businesses including Patisserie Valerie, The Bread Factory and Red Hot World Buffett, said that he is not interested in going back.

“No, I wouldn’t buy it,” said Mr Johnson in an interview with The Telegraph.

“I did actually at one point, when it was rather smaller, try to buy it back, but I think you can’t go back and repeat yourself, it’s boring. I still think Pizza Express is a fabulous formula. But the challenge is how mature a business it is, how many more stores can they open? That is the challenge.

“And also I tell you the other challenge – discounting. We didn’t discount when I was at Pizza Express, ever. It’s what killed Pizzaland and Deep Pan Pizza – as well as horrible pizzas.

“You don’t want to be the person that’s paying £7.45 for the margherita and the neighbouring table has got a two-for-one. That’s really annoying, I think.”

Mr Johnson and Mr Osmond took control of Pizza Express in 1993 when it had 12 branches, and sold out in 1999, by which time it had 250. Today, Pizza Express, which is controlled by Cinven’s Gondola Holdings, has 477 sites, 421 of which are in the UK and Ireland.

Mr Johnson said he is instead focused on continuing to expand Patisserie Holdings, which owns Patisserie Valerie and four other bakery brands.

Results due to be filed at Companies House this week will show the business made a pre-tax profit of £4.7m on sales of £60.1m in the year to September 2013 and Ebitda – earnings before interest, tax, depreciation and amortisation – of £12.3m against £9.9m the prior year.

Mr Johnson said that recent market research conducted for the company estimates potential for a further 200 Patisserie Valeries, on top of the 89 current sites.

“There are certain enduring food brands that have a classic appeal, that will survive the fashions and the ups and downs. I think part of our attraction is that we are not a fad, we are a classic.”

He also refused to deny earlier reports that he and chief executive Paul May are considering a stock market float, valuing the business in the region of £150m.